Is there any script or applecation can I use it to list files and subdirectories under any website

it's mean ,, I want to see all files and subdirectory for example under www.xyz.com

and

also

I have a link has one file
when I went to this link , it gaves me white page , it means this page is secure
and i tried to view source for this page , it comes to me empty page
how I can view the original source for this page